Is the Stanford Algorithms course a good or equal substitute? I started the Princeton one, but the homework was... just not what I would have expected or often threw me for a loop.
If by "Introduction to Algorithms" we mean the infamous book by Cormen et al...
When I propose to use it to prevent sea rise by drying the sea I only half jest. It's IMO one of the worst books to use except as reference when you already have a good grounding.
0. Do not touch "Introduction to Algorithms" until you are in a dream job.
1. CS 61A: The Structure and Interpretation of Computer Programs https://cs61a.org/
2. CS61B: Data Structures http://datastructur.es/sp16/
3. Coursera: Princeton Algorithm https://coursera.org/learn/algorithms-part1
4. CMU 15213 CSAPP https://courses.cs.washington.edu/courses/cse351/16sp/videos...
5. Keep moving.